Mark Levinson No.526 preamplifier

The Mark Levinson No.526 is the first preamplifier designed by a new 12-person team led by Todd Eichenbaum, director of engineering at the Harman Luxury Audio Group's Engineering Center of Excellence (ECOE), in Shelton, Connecticut. Designed to fit the price niche between the company's least and most expensive preampsthe No.326S ($10,000) and No.52 ($30,000)the No.526 costs $20,000.

The new preamp is fully balanced from input to output, direct-coupled, and in key areas employs military-spec thin-film or tantalum-nitride resistors. While the top-of-the-line No.52's power supply is in a separate housing, the No.526 occupies a single case; nonetheless, it has things the No.52 doesn't: a DAC that can accept 32-bit data, a newer-design class-A phono circuit, a headphone output, a front-panel polarity switch, Harman's Clari-Fi digital-restoration modulewhich scans for file type (and thus degree of compression) and then uses existing data to guide it in restoring "waveform deficiencies"and a defeatable, fourth-order, 80Hz high-pass output filter for use in a surround-sound system or with a subwoofer.

Harman's ECOE facility does only research and designthe No.526 is manufactured by Mack Technologies, in nearby Westford, Massachusetts. Besides having state-of-the-art tools and computer-driven machines for metalworking, surface mounting of individual components, wave soldering, and assembling printed circuit boards, Mack can track every circuit board they make, and organize the information into an easily retrievable database for service and quality control.

High Build Quality
The No.526's enclosure is made of 6000-series aircraft-grade aluminum. Inside, each function has its own printed circuit board (PCB): one each for the line-level amplifier, phono preamp, digital processing, and USB inputs. These PCBs are positioned to isolate their low-level circuits from the power supplies.

At the 2017 Consumer Electronics Show, Todd Eichenbaum removed a No.526's top panel to give me a tour of the circuit layout. First he pointed out a steel-shielded box just behind and running the full width of the front panel; as in the No.326, this box contains the power supplies and the mains transformer. Behind this box are, from left to right: a shielded tunnel for the mains wiring; the left channel's line-level circuitry; analog input and output circuitry; and the right channel's line-level circuitry. Control circuitry is centered at the rear of the preamp, with other circuitsincluding the phono stage, DAC, and Clari-Fi modulepositioned above or below the line amplifier board.

Circuit Design
The No.526's left- and right-channel signal paths are fully discrete, mirror-imaged, and dual-monophonic. It has high-linearity switches for each of its six analog inputs (two XLR and four RCA, the latter including one phono input) and six digital inputs (one XLR (AES/EBU), two RCA (S/PDIF), two TosLink (S/PDIF), and one asynchronous USB Type B). The Offset function in the setup menu lets the user match the volume level of each input to the others. The No.526's remote control gives you complete control of its highly intuitive setup menu, and lets you select sources and adjust the volume.

Harman calls the No.526's signal path Pure Path, a term used throughout the Mark Levinson line to describe their combination of Folded Cascode circuit topologybuilt with junction field-effect transistors (JFETs) and bipolar junction transistors (BJTs)with a fully balanced, dual-mono, and ultimately direct-coupled signal path, intended to achieve high gain, low noise, wide bandwidth, and excellent linearity. Other design elements used in the No.526 preamp, including its R-2R ladder volume controlinstead of a traditional potentiometerare also described by Harman as elements of their Pure Path philosophy. Relays select different combinations of resistors so that the volume can be adjusted in precise increments of 0.1dB from 0 to 70dB.

The No.526's phono stage has discrete components and operates exclusively in class-A. Designed for optimal flexibility, it allows the user to select between settings for moving-magnet or moving-coil cartridges, the former offering five capacitive load settings and the latter offering three gain levels and ten resistive load settings. Also offered is an infrasonic filter switch, to reduce the audible effects of record warps and turntable rumble.

The No.526's DAC is identical to the one used in the No.585 integrated amplifier; for all the details, see my review of the No.585 in the December 2015 issue. Briefly, it uses a C-Media 6632A processor, a 32-bit ESS 9018K2M Sabre DAC chip, an all-discrete current-to-voltage converter stage, an antialiasing filter, and the ESS chip's proprietary jitter-rejection circuit. Like the No.585's, the No.526's menu lets you choose among three filter characteristics for digital streams with PCM content: Fast (steep) rolloff, the default; Slow (gradual) rolloff; and MPHAS (Minimum Phase), with steep rolloff of the high frequencies but a minimum-phase impulse response. The asynchronous USB Type B input for DSD has selectable low-pass filter values of 47 (default), 50, 60, and 70kHz. You can also toggle between DPLL bandwidth settings of Normal (default) or Wide. The manual advises using Wide only if you consistently hear dropouts or noise; otherwise, leave DPLL set to Normal.

Controls and Input/Output Interface
The No.526's front panel resembles those of other Mark Levinson preamps, including the No.52 and No.585: a central alphanumeric display flanked by large Input and Volume knobs, with a Headphones jack in the far lower left corner and a Standby button in the far lower right. Below the display are six pushbuttons, from left to right: Polarity, Setup, Enter, Display Intensity, Balance, and Mute. The No.526's setup menu is accessed via the Setup and Enter buttons, or via pushbuttons with identical functions on the handheld remote.

At the center of the rear panel, at the top, is a row of eight control connectors (see below). Below these are the Analog Inputs described earlier and a single row of six Digital Inputs: one XLR, two RCA, two optical, and one USB. At the far right are the main power switch and IEC power inlet. The two pairs of Main Outputs, RCA and XLR, can be individually configured for fixed output or output variable by the volume control, and/or output either full-range or high-pass filtered at 80Hz, 24dB/octave.

The control connectors are: Ethernet, for connection to a network; USB Type A, for updating the No.526's firmware; 3.5mm mini-jack, for an external infrared receiver, should the preamp be shut up in a cabinet; six-pin RS-232, for external control by a master control system from, say, AMX or Crestron; micro-USB, so that the No.526 can be recognized on a network; and one 12V input and two 12V outputs, to allow a remote signal to turn the preamp on and off. For daily use, the preamplifier has two operating modes, Standby and On; for long absences or lightning storms, it can be turned off entirely using a rocker switch on the rear panel.

The No.526 has no dedicated tape input or tape loop for monitoring tape recordings in real time. Eichenbaum explained that there is "not much call for that functionality these days, since the demise of three-headed analog tape recorders." To duplicate the tape loops found on earlier Levinson preamps, such as the No.326, he suggested a workaround: Set the No.526's XLR outputs for variable output, to drive the power amplifier(s) and speakers, and its RCA outputs for fixed output, to serve as a Tape Out. A separate RCA input could be assigned to receive the music signal from the tape head, but not to perform real-time monitoring of a recording.

Installation and Connections
My first step was to swap out my current preamplifier, a Bryston BP-26, to make room for the Mark Levinson No.526. The BP-26 sat in my wall rack on a roll-out shelf 24" wide by 16" deeptoo shallow for the 19"-deep Levinson. Todd Eichenbaum, who'd personally delivered the review sample, pulled the shelf out all the way, and positioned the No.526 on it sideways, facing my listening chair, to give me and the remote control line-of-sight access to its front panel.

I'll guess that you meant that it wasn't worth destroying your next three years financial life to own, so you sent it back. I would too, even if they let me have it for dealer cost ( about 50% ) or used/demo type of scratched damaged level ( 35% of Retail price ).

I think this "to die for" concept started with the early Christian Martyrs but it kinda died out till recently when wannabe up-scale women started shopping at Lord & Taylor, ISIS got it from them and reallllllly means it. ( ouch )

Tony, I wish your rant had some new information. But, nice guy that I am, I'll throw you a bone here - one that you might have missed in the review:

"....nonetheless, it has things the No.52 (the $30k preamp) doesn't: a DAC that can accept 32-bit data, a newer-design class-A phono circuit, a headphone output, a front-panel polarity switch, Harman's Clari-Fi digital-restoration module—which scans for file type (and thus degree of compression) and then uses existing data to guide it in restoring "waveform deficiencies"—and a defeatable, fourth-order, 80Hz high-pass output filter for use in a surround-sound system or with a subwoofer."

So there - you see? User with $30k preamp sees that the $20k preamp has new goodies that the $30k preamp doesn't have, and so Levinson obviously needs to create a new $40k preamp. Just sayin'.

I still give the Front Cover to Mytek Brooklyn, it has MQA, it can even do Surround, for a measly $2K.

Only a very few will end up owning the ML ( the "Luxury" buyers ).

Besides, it's the actual quality of the recording that matters here, the sound quality differencial of DACs seems to be rather minute slivers overshadowed by stuff like iFi USB Cable technologies.

But, lets not tell the Orthodontists any of this. ML, Harmon and Samsung need these Good/Better/Best "Luxury" DACs to be a Sales Success.

It's safe to say that I've never enjoyed the Applause of Admiring Customers but I always seem to get re-hired after completing their troublesome projects. I'd be damn lucky to assemble a kit DAC and have the darn thing actually work. Annnnnnd, if it did actually work, I'd doubt that I could discern if it sounded any good.

However,
Give me a Lamb Transfer Machine and I'll have it singing like a International Harvester.

Tony in Michigan

ps. the Schiit Yggy DAC has 7 individual Circuit boards that each look as jam packed as the one board of this ML. the Yggy cost = $2,500, go figure! ( it might even sound as good or better )

I don't know all of that gear (very little of it actually), so I enquire for my own use starting with certain principles. For example, if I want the most realistic sound, I know I will need a good-size room and big speakers that can output realistic sound. There's no getting around that, unless you intend to compromise. Then I need amps appropriate to the speakers, and from there work backward to the source (CD, digital etc.) Do you think that people who want the most realistic sound, who are buying the big speakers for their listening room, are inclined to skimp on amps and DACs and source components? Do you decide on those items mainly by price? I'd like to read case studies of audiophiles who want the real thing, but are able to get there with relatively cheap ancillary components. Those systems should be an interesting study.

I'm old school Scotland ( Linn ). I start with a darn good source and darn good recordings and build out from there. Speakers come last.

In the USA, folks start with Speakers and build back to the Source.

I can recall a CES ( 1980s ) where the Cerwin Vega guys were playing Sheffield Lab records making their crappy but gigantic loudspeakers sound pretty darn good. But... try playing really crappy recordings on a well done Wilson system and you're gonna get really crappy sound.

Most vinyl was made to be played on really crappy Sears & Roebuck crappy record changers. We could forgive ( back then ), the World was a nicer place.

In that case, I will confess I'm still skeptical about Class D, in spite of our advances in electronics. People say they can hear the difference between 96 khz and DSD 384 or what have you, and they *can't* hear the difference between Class A and Class D (all other features being equal of course)?

I see Me. Kaz is on one of his non-germane rants. Always amusing/pitiful. If Mr. Greenhill compares the Levinson to the Theta Prometheus monos I can relate as I own his review samples. In relating to the clarity/dynamics it would seem to be a good pairing and am sorry the test could not have included them.

Hi Tony. Thank you for clarifying. Wishing you good health moving forward.

You mention HF hearing extending to 8KHz. You know, lately, I've undertaken considerable interest in what "lies" in the lower frequencies (i.e. 1-Hz to 100 Hz. range -and then extending to 1-5KHz.)

I believe the notion of physical hearing acuity above 10/15K KHz., to be nothing more than an interesting observation.

Designer's (and listener's) should be far more concerned with 'Low-Frequency' resolution, as it is here, within these fundamental (core) frequencies where ALL of the audio signal information rests upon.
If LF resolution is absent -so too must all (harmonic) frequencies that follow.
Bottom line: HF hearing to 8 KHz. should NOT prevent one from enjoying the full-bandwidth of music; 8-KHz. remains quite high.

Moving on, oh yes, Tesla, Battery/Fuel-Cell Power is both long-overdue and quite necessary.

More than enough trillions of dollars have been harvested from crude oil. Enough billionaire, millionaire's have polluted their pockets for the past 100-years -as has governments "take". Nothing quite like so much money that "everyone" can take a healthy/happy slice.

John, do you happen to have the measures of the residual noise at open input? From Figure 3 I eyeballed it to be around 0.04 mV, which appears quite good. But it would be interesting to know the precise value.

It's a very good looking product (just look at the interior photos), the Mark Levinson No. 526 Preamplifier ($20,000.00 USD), and the Clari-Fi digital technology sure sounds interesting, but what has happened to Mark Levinson?

It is 2017, and the SN ratio is 97 db (100 dB, A-weighted). What of 24-bit audio? What of at least 130 dB?

For $1750, back in 1973, Mark Levinson made the LNP-2 Preamplifier, which boasted dynamic range of > 130 dB.

http://www.preservationsound.com/?p=6060

Today, for about $2000.00 USD you would find that in a product like the Brooklyn MyTek DAC.

https://mytekdigital.com/hifi/products/brooklyn/

To my eye, Mark Levinson of today has gone a bit McIntosh, in the box-preservation department, harking back to the days of the 33 (1990's).

Would I take a Mark Levinson No. 526 and associated components over a Daniel Hertz ML 6L Preamplifier and ML 5L Monoblocks?

I own a No. 523 and a pair of No. 536's. My DAC is a Bel Canto 2.7. I've found the clarity of sounds and the spaciousness between voices in harmony is remarkable. I don't have experience with other fine DACs or Preamps as these are my first non-AVR purchases, but I couldn't be happier with what I hear coming from my B&W 800's. However, the quality of a recording is revealed to an extreme, and a great deal of good music is noticeably less appealing on this system. On the other hand, fine recordings are magical.

When referring to the Koss Pro 4AA, do you mean the original? Decades old? Whenever I put on a pair of those, I was reminded of Uncle Fester with his head in a vice. Painful? Maybe, but he sure looked happy.

Why in the world they'd offer the No. 526 (with built in DAC, S/W cut-off filter and such) is a bit foolish.

Have a stand-alone unit for this --or better (cheaper) yet, a simple open space within the unit (say/call it a "520"-series) and then option a DAC, Phono stage, Server/Renderer or other 'processing' circuits (a la carte) satisfying customer requirements.

All three (pre's) are a waste of skews -- No. 326S, 526 and a 523 ??

Instead of a sensible, high-tech "modular" build (or better yet, 1-U/2U size) separate chassis), ML has made the entire exercise unnecessarily complicated.
The best stuff is always separates. Yet here (No.526), we have a "chinsy" 4"X 6" circuit board stuffed in the center of the chassis --for an additional $5-K !!??

The stand-alone No.52?(dual-chassis) flagship preamplifier is fine, but a $20-K PRE/DAC --seriously ?

I have an old ML No. 32 and it still reveals its transparent signature. I don't know why ML would install a DAC when they always harped about noise. Why not separate? The headphone jack and phono "card" or "stage" is convenient. The phono stage for my unit was about an $1800 option. They were easily installed by the owner or dealer. My front end is digital so I opted out. I wish I had gotten it.

My display is also more easily seen. The red numerals on the 32 are much larger reminiscent of the old style whereas in comparison, the red numerals on the 526 are really small. The features on the 526 reflect rapidly changing audio market and that's good. I'd like to hear a 526 to see if it has improved but there isn't a dealer near me (Atlanta). Audio appears to be getting more complicated with those bloated video/audio processors and the like.

Levinson went under a while ago and is slowly making its way back into the trust of former owners and the few dealers that remain. Many were shafted. I'm leery of Harmon's influence on that DNA and Levinson's commitment to quality and service like they were 20 years ago. The sound from my system is just so good.

My gear is all ML and is in need of service. That's something I hadn't thought about (like recapping etc). ML doesn't service their product anymore. They used to do it and I trusted them as manufacturer. Is anyone aware of a reliable company who knows ML gear and has a good rep? NYC area or the SE?